DETERMINATION OF MINERALS. 403 
natrolite, but twinned, with converging strie on 7-? as in figure on 
p-. 299; B.B. sometimes curls up, fuses very easily. — 
GWIELINITE, p. 301. H.=45; G.=—2-2°2 ; in smali and short hex- 
agonal or rhombohedral cryst. ; B.B. fuses easily. 
PAILIPPSITH, p. 302. H.=4-45; G.=2°2; intwinned crystals ; 
B.B. fuses rather easily. . 
LAUMONTITE, p. 293. H.=3:5-4; G.—2-2-24; white, reddish ; 
crystals become white and crumbling on exposure to the air; B.B. 
fuses rather easily. 
Pectolite (p. 293), and Analcite (p. 299), imperfectly gelatinize. 
b. Hydrous; fuse with much difficulty. 
CALAMINE, p. 157. H.=4:5-5; G.=3:15-3-19 ; white, greenish, 
bluish ; orthorhombic in crystals ; B.B. fus. with great difficulty, re- 
action for zine and none for iron ; hydrous. 
SEPIOLITE, p. 306. White ; soft and almost clay-like, also fibrous ; 
B.B. fuses with difficulty, with cobalt solution reddish ; hydrous. . 
PYROSCLERITE, p. 317. H.=3 ; G.=2°74; micaceous ; B.B. fuses 
on thin edges. . 
c. Anhydrous. 
a NO REACTION FOR SULPHUR ; NO COATING ON COAL. 
NEPHELITE, p. 269. H.—5'5-6 ; G.—2°5-2°65; hexagonal prisms 
and massive ; vitreous. with greasy lustre ; white, ywh, gyh brown, 
rdh ; B.B. fuses rather easily. 
WOLLASTONITE, p. 244. H=45-5; G.=2°75-2:9; white, gyh, 
rdh, bnh; B.B. fuses easily. 
SODALITEH, p. 270. H.=5'5-6; G.=—2:13-2:4; white, blue, red- 
dish ; in dodecahedrons and massive ; B.B. fuses not very easily. 
WILLEMITE, p. 157. H.—5:5; G.—8-9-4:3 ; white to greenish, 
reddish, brownish; B.B. glows and fuses with difficulty ; reaction 
for zinc and none for iron ; anhydrous. 
2. REACTION FOR SULPHUR B.B. WITH SODA. 
HAUYNITE, p. 270. H.—5°5-6 ; G.—2:4-25; blue, greenish; iso- 
metric, in dodecahedrons, octahedrons ; B.B. fuses with some diffi- 
culty. 
DANALITE, p. 256. H.—5-5-6 ; G.=—3-427; isometric; flesh-red to 
gray ; B.B. fuses rather easily, and gives reaction for manganese: 
and zine. 
B. Not Gelatinizing. 
1. STRUCTURE EMINENTLY MICACEOUS, SURFACE OF FOLIA 
MORE OR LESS PEARLY; H. OF SURFACE OF FOLIA 
NOT OVER 3°5; ANHYDROUS OR HYDROUS. 
MUSCOVITEH, BIOTITH, PHLOGOPITE, LEPIDOLITE, LE- 
PIDOMELANE ; for distinctions see pp. 266-268. Anhydrous, 
